A known slide door apparatus is disclosed in Japanese Patent Laid-Open Publication No. Hei. 9-317324. In this apparatus, when an electrically operated driving mechanism is turned on, the resulting rotation of the driving mechanism in one direction moves the slide door in its opening direction, thereby opening the opening area formed in the lateral side of the vehicle body. The resulting rotation of the driving mechanism in the other direction moves the slide door in its closing direction to thereby close the opening area in the lateral side of the vehicle body.
The slide door is supported by rails secured to the vehicle body in such a manner that a roller provided on the slide door moves along each of the rails. A geared wire is interposed between the driving mechanism and the slide door, and this geared wire is pulled and pushed by the driving mechanism to respectively open and close the slide door.
When forces are applied from the driving mechanism to the geared cable for opening and closing the slide door, the horizontal component of the force is transmitted to a side wall of the rail, and this causes a deformation of the side wall of the rail, thereby disturbing or adversely affecting smooth movement of the roller. One proposal for addressing this problem involves reinforcing the side wall of the rail. However, this increases the overall weight of the rail, a result that is not very acceptable due to the desire to utilize vehicle components that are as light as possible.
Accordingly, a need exists for a slide door apparatus for vehicles in which the guide rail, or a side wall of the guide rail, is reinforced without increasing the weight of the rail.